A Look at Amazon Basin Seasonal Dynamics with the Biophysical ...

Linking seasonal inundation with ecological, hydrological and biogeochemical processes in the Amazon basinJohn M. MelackUniversity of California, Santa BarbaraInstitute for Computational Earth System Science, University of California, Santa Barbara, CA 93106, USAmelack@lifesci.ucsb.eduSeasonally inundated areas cover large areas of the Amazon basin and are important components of theecology, hydrology and biogeochemistry of the basin because they modify riverine discharges and chemicalcomposition and are significant sources of greenhouse gases to the atmosphere and fish to humans. Recentadvances in active and passive microwave remote sensing are providing regional information on temporalchanges in inundation and aquatic vegetation. Multiple aspects of LBA require are incorporating thisinformation. For example, combination of remotely estimates of inundation with extensive measurements ofdissolved carbon dioxide for the central Amazon indicates that evasion to the atmosphere of carbon dioxide isabout ten times the fluvial export of organic carbon by the Amazon River. The organic carbon fueling theevasion appears to be largely derived from riparian and floodplain vegetation, illustrating the importance ofterrestrial-aquatic-atmospheric exchanges. Further, the evasion of carbon dioxide and methane from Amazonwetlands appears to balance much of the uptake of carbon dioxide by terrestrial vegetation. Amazon fisheriesare important to the income and nutrition for many people living in the region, and fish yields have strongstatistical relations with maximum or minimum flooded areas.